1. Field of the Invention
The present invention relates generally to the field of convergent exercise machines using resistance for exercising the upper torso and arm muscles for a complete natural joint articulation of shoulders, elbows and wrists, and more particularly to a method and exercise machines having a pair of exercise arms, attached on at least one pivot, which are moving in a machine-determined circular exercise motion path, where the position of the handles attached to the arms can be adjusted for varying the diameter of the machine-determined circle, and where each handle allows the user""s hand to move in a non-circular motion path, to facilitate complete natural articulation of the user""s arms.
2. Brief Description of the Prior Art
Free weights are popular among many weight lifters because the lifting movements are not restricted to prescribed planes of motion and at prescribed angles. Conventional exercise machines provide a workout for the upper torso and arms with limited benefits. Conventional convergent plane free-weight machines were introduced by Hammer Strength Corporation in late 80""s and covered by U.S. Pat. Nos. 5,050,873, 5,181,896, 5,135,456 and 5,044,631, issued to Jones. Hammer machines typically operate with a set of levers, pivotally connected to the frame behind and above the seat, and they pivot from a wide to a narrow position.
In Hammer machines, a pair of independently pivoting arms is suspended on a pair of axes, defining arcuate exercise motion paths centered at the respective pivot axis of each pivoting arm. The arms pivot in two convergent planes, which allows for standard exercise movements to be performed to achieve articulation of the shoulder and elbow, but the distance between the handles and the user""s body cannot be varied to accommodate for longer or shorter arms. Although Hammer machines constrain the user to the machine-determined exercise motion paths, they have the same starting position for all users, thus benefiting the tall users, and do not provide an optimum exercise motion path, comfortable and adequate for smaller users.
Other types of conventional machines allow the user to define his own arcuate exercise motion path. An example of these machines is disclosed in U.S. Pat. No. 4,949,951, issued in 1990 to Deola. Deola""s machine has a suspended U-shaped pivoting member, resembling a conventional press arm, with two bar members with handles, connected to the lower ends of the U-shaped member by universal joints. However, the resistance of this machine is only associated with the pivoting U-shaped member, and the user does not get full benefit of the movements at the universal joints of the handles. Further, since the user has a complete freedom of movement of the handles, and the handles and arms are moving in opposing planes, the motion is very uneven and jerky. Thus, there is a long learning curve to develop the correct feel for the machine.
Body Masters Sport Industry, Inc. has a machine model CH 504, which includes a pair of exercise arms, each of which pivots about its own respective vertical axis located approximately in line with the user""s shoulder joint. Handgrips are suspended from the overhead exercise arms and rotate forwardly and inwardly through symmetric circular arcs, concave with respect to the user""s torso. The machine can vary handle movement to adjust for varying arm lengths, and allows for complete articulation of the shoulders, but provides no benefits to biceps and triceps, since the elbows are fixed.
U.S. Pat. No. 5,437,589, issued in 1995 to Habing, describes an upper body exercise machine with a machine-determined exercise motion path, which is also optimally suited for tall people, because the user is confined to start at a pre-determined position and the ending point depends on the length of the user""s arms. The machine has a pair of symmetrically articulated exercise arm assemblies, each of which is pivotally attached to the frame with a complicated four-bar linkage. In one embodiment of the Habing device, the geometry of the arms and their two pivot points are arranged so that the handgrips of the arms follow non-circular arcuate exercise motion paths. The exercise motion paths arc outwardly and converge as the handgrips are moved forwardly, in a plane slightly inclined from a horizontal plane, so the user need not support the weight of the exercise arms.
In one embodiment of Habing device, the exercise motion paths are symmetrical circular concave arcs, concave to the user""s torso, lying in a plane slightly inclined from horizontal, and perpendicular to the axes of the pivots. However, the handgrips are fixed and not adjustable. Another disadvantage of the Habing machine is that the series of pulleys and cables are designed in such a way that the resistance depends upon the angles at which the cables attach to the arms, and thus the machine does not follow the variable force curve for the muscle being exercised.
The preceding and other shortcomings of prior art systems are addressed and overcome by various aspects of the present invention, which consist of convergent exercise machines for exercising the upper torso and arms, to provide all of the conventional exercises, commonly practiced and presently only available using the free-weights, with improved exercise results.
One embodiment of the present invention is a method for natural joint articulation of shoulders, elbows and wrists, using a convergent exercise machine for exercising the upper torso and arm muscles. The circular exercise motion path is machine-determined and defined by a pair of exercise arms, each arm rotating about an arm pivot axle and having a handle assembly. The diameter of the circular exercise motion path is adjusted for the user""s arm length. The method includes the following steps: defining the position of the arm pivot axle so that the movement of a handle assembly pivot is coincident with the machine-determined circular exercise motion path, and defining the position of the arm pivot axle at a location in a plane parallel to the plane positioned through the user""s shoulder joints and at a lateral displacement from it, at a location further into the exercise stroke than the plane positioned through the user""s shoulder joints. The method has a further step of adjusting the position of the exercise arm handles to accommodate user""s arm length. The handle assembly pivot is preferably a wrist joint accommodating pivot.
Another embodiment of the present invention is a convergent exercise machine using resistance for exercising the user""s upper torso and arm muscles, for complete natural joint articulation of shoulders, elbows and wrists. The machine has a support frame having a support frame member and at least one arm pivot axle connected to the support frame member, and a pair of exercise arms rotatably attached to the arm pivot axle. The exercise arms move in a machine-determined circular exercise motion path having a predetermined diameter, and each exercise arm has a first end rotatably connected to the arm pivot axle and a second end having a handle assembly mounted to the exercise arm and adapted to be grasped by the user""s hand and pulled toward or away from the user.
The handle assembly pivot is preferably a wrist joint accommodating pivot. The position of the arm pivot axle is located in a plane parallel to the plane positioned through the user""s shoulder joints and at a lateral displacement from it, and at a location further into the exercise stroke than the plane positioned through the user""s shoulder joints. The position of the arm pivot axle is located so that the machine-determined circular exercise motion path is coincident with the movement of the wrist joint accommodating pivot from start to finish of an exercise, to accommodate the natural musculoskeletal makeup of a person performing an exercise.
A variable resistance system, which has at least one weight and a load multiplying eccentric cam system, is used to provide a varying weight resistance during the displacement of the exercise arms, in order to train all muscle groups in the user""s upper torso and arms through the natural strength curve.
In two embodiments of the present invention, representing machines used with pressing movement, the handle assembly has a handgrip stirrup which is offset forward of the wrist joint accommodating pivot. The wrist joint accommodating pivot is located in line with the user""s wrist joint for rotation of the user""s wrist joint about the wrist joint accommodating pivot. In two other embodiments of the present invention, representing machines used with pulling movement, the wrist joint accommodating pivot is located in line with the user""s hand and in line with the handgrip stirrup.
In addition, each type of the machine of the present invention can be made with a singular arm pivot axle, two co-linear arm pivot axles or two co-planar parallel arm pivot axles. By using the techniques of the present invention, much more compact machine configurations are obtainable, thus considerably decreasing the floor area occupied by these machines.
The foregoing and additional features and advantages of this invention will become further apparent from the detailed description and accompanying drawing figures that follow. In the figures and written description, numerals indicate the various features of the invention, like numerals referring to like features.